changed to object_getClass object_setClass to fix crashes in iOS9

JSONKit.m

@@ -677,7 +677,7 @@ + (id)allocWithZone:(NSZone *)zone
   NSCParameterAssert((objects != NULL) && (_JKArrayClass != NULL) && (_JKArrayInstanceSize > 0UL));
   JKArray *array = NULL;
   if(JK_EXPECT_T((array = (JKArray *)calloc(1UL, _JKArrayInstanceSize)) != NULL)) { // Directly allocate the JKArray instance via calloc.
-    array->isa      = _JKArrayClass;
+    object_setClass(array, _JKArrayClass);
     if((array = [array init]) == NULL) { return(NULL); }
     array->capacity = count;
     array->count    = count;
@@ -928,7 +928,7 @@ static void _JKDictionaryResizeIfNeccessary(JKDictionary *dictionary) {
   NSCParameterAssert((keys != NULL) && (keyHashes != NULL) && (objects != NULL) && (_JKDictionaryClass != NULL) && (_JKDictionaryInstanceSize > 0UL));
   JKDictionary *dictionary = NULL;
   if(JK_EXPECT_T((dictionary = (JKDictionary *)calloc(1UL, _JKDictionaryInstanceSize)) != NULL)) { // Directly allocate the JKDictionary instance via calloc.
-    dictionary->isa      = _JKDictionaryClass;
+      object_setClass(dictionary, _JKDictionaryClass);
     if((dictionary = [dictionary init]) == NULL) { return(NULL); }
     dictionary->capacity = _JKDictionaryCapacityForCount(count);
     dictionary->count    = 0UL;
@@ -2596,7 +2596,7 @@ static int jk_encode_add_atom_to_buffer(JKEncodeState *encodeState, void *object
 
 
   BOOL   workAroundMacOSXABIBreakingBug = (JK_EXPECT_F(((NSUInteger)object) & 0x1))     ? YES  : NO;
-  void  *objectISA                      = (JK_EXPECT_F(workAroundMacOSXABIBreakingBug)) ? NULL : *((void **)objectPtr);
+  void  *objectISA                      = (JK_EXPECT_F(workAroundMacOSXABIBreakingBug)) ? NULL : object_getClass(objectPtr);
   if(JK_EXPECT_F(workAroundMacOSXABIBreakingBug)) { goto slowClassLookup; }
 
        if(JK_EXPECT_T(objectISA == encodeState->fastClassLookup.stringClass))     { isClass = JKClassString;     }
@@ -2804,7 +2804,7 @@ static int jk_encode_add_atom_to_buffer(JKEncodeState *encodeState, void *object
           for(idx = 0L; idx < dictionaryCount; idx++) {
             if(JK_EXPECT_T(printComma)) { if(JK_EXPECT_F(jk_encode_write1(encodeState, 0L, ","))) { return(1); } }
             printComma = 1;
-            void *keyObjectISA = *((void **)keys[idx]);
+            void *keyObjectISA = object_getClass(keys[idx]);
             if(JK_EXPECT_F(keyObjectISA != encodeState->fastClassLookup.stringClass) && JK_EXPECT_F([(id)keys[idx] isKindOfClass:[NSString class]] == NO)) { jk_encode_error(encodeState, @"Key must be a string object."); return(1); }
             if(JK_EXPECT_F(jk_encode_add_atom_to_buffer(encodeState, keys[idx])))    { return(1); }
             if(JK_EXPECT_F(jk_encode_write1(encodeState, 0L, ":")))                  { return(1); }